1. Field of the Invention
This invention is directed to a self adhesive decorative covering sheet adapted to conveniently facilitate hand-tearing to a predetermined reduced size. In particular, the covering sheet has been modified with reticulated through-cut microperforations and embossed prescores which are positioned to facilitate cross-tearing along the main, the transverse and diagonal axes of the sheet.
2. Description of the Prior Art
Widespread efforts have previously been made in the provision of sheet coverings, for application to selected surfaces in overlying protective or decorative relation. Much of this effort has been directed to covering sheets incorporating a first layer having a decorative first face, an intermediate layer of adhesive, and a reverse layer comprising a removable siliconized release liner.
Another provision known in the art includes a sheet having a siliconized decorative first face with an adhesive coated reverse face permitting the sheet to be rolled upon itself and readily unrolled without the need for a separable release liner.
This prior art includes the provision of hand-tearable sheets, having predetermined weakness characteristics to facilitate the ready downsizing of a standard sheet, in order to fit and cover a surface of predetermined size.
U.S. Pat. No. 4,380,564 Cancio et al, discloses decorative plastic sheet material intended for shelf liner and other uses, and provides for transverse and longitudinal hand tearing by use of transverse and longitudinal embossed intersecting tear lines, the tearing thereof being facilitated by the use of a dispersed phase of calcium carbonate (chalk) at about 15% of the mix, the plastic being low density polyethylene. In this patent, and their U.S. Pat. No. 4,465,729 the same inventors provide pressure sensitive adhesive protected by a removable liner. Installation of the materials disclosed in both of these patents is frequently cumbersome since the protective release liner backing the adhesive does not incorporate any tear assisting provision. Thus, in order to take advantage of their disclosed sheet tearing capability the prior removal of the release liner is virtually imperative. This can lead to severe problems, since the exposed adhesive surface tends to fold in upon itself, with extreme mutual adherence, the separation of which frequently leads to a permanently wrinkled covering sheet. Covering sheets having a dispersed chalk phase show a propensity to form a white fold line or break-through when creased, which is particularly noticeable in the case of sheets that are decoratively overprinted. Removal after long-term usage may be extremely difficult, due to sheet fragmentation into miniscule pieces, caused by aging embrittlement of the plastic by the calcium carbonate.
U.S. Pat. No. 5,536,546 Nash, discloses linerless labels, having the sheet of label material through-slit laterally and through-cut intermittently, longitudinally, with two sizes of cut, and with intermediate uncut tie portions, to define the individual labels. The slits and cuts are positioned such that the lateral slits each intersects a respective longer one of the longitudinal cuts, so as to provide a clean release of the respective label corners upon tearing. Adhesive and release backing are also provided.
U.S. Pat. No. 5,662,976 Popat et al, discloses laminated cards, for use with ink jet and laser printers, having a face sheet to receive printed material, a backing sheet and an adhesive over portions of the backing sheet, with microperforations that define the individual cards extending through the face sheet and the backing sheet. A release coating is provided over at least a portion of the adhesive.
In the prior art use of self adhesive covering sheets for shelves and the like it has usually been the practice to measure the surface to be covered, transfer the measurements to the outer face of the siliconized release liner along its preprinted gridlines, and cut along those gridlines, using scissors or a razor blade. It is troublesome to accurately achieve straight cuts and right angles along the length and width, in trimming a decorative covering sheet. The resultant inexactitude in sheet size and fit compounds the installation problem in fitting within a cabinet or drawer. Non-conforming or oversized material does not readily adhere precisely in its required location, having an increased tendency for sheet edges to cling to and seal to adjacent side walls of cabinets or drawers, and forming air pockets beneath the impermeable vinyl material. Such air pockets eventually collapse under load, forming unsightly and permanent creases and wrinkles.
The foregoing problems are intensified in the case of self wound liner material having the release coating applied to the decorative upper face. Such coverings frequently become unmanageable, when unrolled, since they are prone to folding upon themselves, with two adherent surface portions mutually engaging, and strongly adhering, leading to sheet deformation, with permanent creases being formed. Installation of this typo of liner requires the application of an oversized covering sheet to the surface to be covered, with folding up of the unrequired edge portions, and subsequent trimming away of the surplus with a razor blade. Since self-wound coverings are more difficult to position, especially within poorly accessed locations such as drawers and cabinets, the formation of air pockets and subsequent wrinkling becomes exacerbated. On occasion, users of both separable release lined and self wound covering sheets are known to puncture the decorative and/or protective impermeable outer layer to release entrapped air, thus mutilating the covering sheet.